The Verizon iPhone 4 has a problem that could cause the phone to drop calls, or be unable to place calls, in weak signal conditions, Consumer Reports engineers have found in lab tests.

The problem is similar to the one we confirmed in July with the AT&T version of Apple's newest smart phone ...

... As noted earlier, there have not been widespread reports of reception difficulties with the Verizon iPhone 4, and Verizon's network, unlike AT&T's, has received above-average scores from our readers for the reliability of its voice service in the past. (Those scores reflect data gathered before the launch of the Verizon iPhone 4.) But given our findings, we believe the possibility exists for individual users to experience the problem since low signal conditions are unavoidable when using any cell-phone network.